Garry Ringrose bagged a hat-trick on his return to Leinster as the province nabbed a winning bonus point to kick off their Champions Cup campaign.
A crowd of 15,080 braved the cold conditions at the RDS to watch Leo Cullen's side wrap up the bonus point inside 45 minutes, with Johnny Sexton dotting down for the fourth try, while Ringrose secured his third with 12 minutes remaining.
Earlier, the classy no 13 had got last year's losing finalists and running with two tries inside the opening quarter hour.
That got the Blues' noses back in front and they never looked back - after a seventh minute converted try by the visitors gave some pause for thought - and Leinster look in decent nick ahead of their testing trip to Lyon next weekend.
Cullen had been forced to adjust to a late change at centre with Rory O'Loughlin replacing Joe Tomane, who suffered a hamstring injury in the eve of game captain's run.
With a vacancy to fill on the bench, Robbie Henshaw was included after recovering from illness and he made a cameo appearance in the last quarter.
Despite the late personnel change, the hosts quickly hit their stride and registered the first try in the fifth minute with World Cup trio Andrew Porter, Sexton and Ringrose combining to send the latter over.
Sexton missed the difficult conversion - and Benetton produced a blistering retort.
Having won a penalty on the edge of Leinster's 22, the visitors chose to kick for the corner rather than for the handy three points and were rewarded with a seven point return.
Their lineout drive brought them to the Blues' try line and Dean Budd twisted in the tackle to score, giving James Ryan no chance.
And former Leinster starlet and Munster out-half Ian Keatley kicked the Italians into a two point lead.
The game's rip-roaring start continued as Leinster made a lot of ground through a slick passing move that resulted in a penalty on Benetton's 10 metre line and a driving lineout maul brought them closer still.
With a penalty advantage, Sexton's up and under almost resulted in a try.
But moments later Ringrose made sure of it as he powered through Benetton skipper Alberto Sgarbi's challenge to touch down, with Sexton tapping over the conversion in front of the posts.
The momentum of the contest was almost instantly lost when Caelan Doris, the Leinster no 8, was forced off for a HIA.
But Leinster gained traction once more from a timely Devin Toner lineout steal from a Benetton throw close to the Blues' line.
When Nasi Manu tackled Sexton off the ball seconds later, it provided the home side with a further attacking platform - as did Nicola Quaglio's high tackle on Champions Cup debutant Ronan Kelleher in the 28th minute.
The visitors also had to send tighthead replacement Tiziano Pasquali in for Marco Riccioni (HIA) before a Leinster scrum put-in just seven metres out from Benetton's line.
Deegan made ground off it before Kelleher maintained his eye-catching scoring spree to dive over for his seventh try in six games.
Sexton made it 19-7 with his conversion with eight minutes of the half remaining. Then Keatley had a chance to make it a nine-point game before the break, his long-range penalty fell just short.
A classy Ringrose break put Leinster on the front foot from the restart but, after taking a Sexton cross-field kick, Dave Kearney chose to go inside instead of hugging the touchline with the try line in view.
But the Blues were in the mood to wrap up the bonus and it came just four minutes into the half.
Sexton's midfield break carved open Benetton's defence and Josh van der Flier was unselfish in feeding the ball back to the out-half to score, and the jubilant Sexton added the extras.
The five points secured, Leinster proceeded to fall asleep at the wheel.
Cullen's charges conceded a second try when Hame Faiva charged through for a converted try in the 51st minute.
But dogged defence kept the Italians at bay after the hour mark as they looked for the lifeline of a third try.
Instead, it was Leinster who scored next with man of the match Ringrose delivering again, running an unstoppable line to finish - before Benetton finished the scoring through Luca Sperandio late on.
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